Smallest caliber for bear?

[Rustynuts]

So my son will be old enough for bear next spring.......What is the lowest caliber a person should consider?
He is very tall for his age (5'1")and weighs 95lbs.I was thinking 308 but I'm sure there are other options.

[Andythehillbilly]

I don't think the caliber is as important as his comfort level with the rifle. If he can shoot it good, any well placed shot will put a bear down.

[james_m]

The lowest you can legally hgo will work just fine. - .243